A Vascular Plant Red List for England Drosera anglica Huds. © Jonathan J. Graham Drosera anglica is illustrated here and scattered across lowland England, but a pictured on the front cover not simply combination of many factors including peat because it has an apt name for this report. digging, eutrophication and technological Regrettably, the loss of this species from many advances in land drainage resulted in rapid, of its historical locations is emblematic of the widespread and irreversible habitat loss and plight in England of many small specialist the fragmentation of populations, so much species of highly infertile soils, such as Erica so that D. anglica is now considered to be tetralix with which it is pictured. Drosera ‘Endangered’ in England. anglica was once relatively widespread and A Vascular Plant Red List for England P.A. Stroh1, S.J. Leach2, T.A. August3, K.J. Walker1, D.A. Pearman1, F.J. Rumsey4, C.A. Harrower3, M.F. Fay5, J.P. Martin2, T. Pankhurst6, C.D. Preston3, I. Taylor2 With assistance from England Vice-County Recorders of the Botanical Society of Britain and Ireland 1 Botanical Society of Britain and Ireland 2 Natural England 3 Centre for Ecology and Hydrology 4 Natural History Museum 5 Royal Botanic Garden Kew 6 Plantlife Copyright © BSBI 2014 Designed by LTD Design Consultants, 54 Warwick Square, London Published by the Botanical Society of Britain and Ireland SW1V 2AJ. www.ltddesign.co.uk 57 Walton Road, Shirehampton, Bristol, BS11 9TA www.bsbi.org.uk Printed and bound in Great Britain by Henry Ling Limited, Dorchester. www.henryling.co.uk The Botanical Society of Britain and Ireland (known as the BSBI) is a company limited by guarantee registered in England and Wales This book should be cited as: (8553976) and a charity registered in England and Wales (1152954) Stroh, P.A., Leach, S.J., August, T.A., Walker, K.J., Pearman, D.A., and in Scotland (SC038675) Rumsey, F.J., Harrower, C.A., Fay, M.F., Martin, J.P., Pankhurst, T., Preston, C.D. & Taylor, I. 2014. A Vascular Plant Red List for Photographic copyright © The Owners England. Botanical Society of Britain and Ireland, Bristol. Line drawing copyright © Jonathan J. Graham ISBN XXXX A Vascular Plant Red List for England Summary The results detailed in this vascular plant but also in the decline in distribution by Red List present for the first time the 20% or more of a suite of ‘Near Threatened’ current state of England’s flora measured species, some of which were previously against standardised IUCN criteria. Almost assumed to be widespread and with relatively one in five species has been assessed as stable distributions. The strategic approach threatened, with many more species assessed advocated by Lawton et al. (2010) to restore, as ‘Near Threatened’. The destruction and create and connect extant habitats at the transformation of semi-natural habitats across landscape scale is essential if the declines the English landscape since the publication identified in this and other Red Lists are to be of the first Atlas of the British Flora (Perring arrested. Such an approach demands long- & Walters 1962) is well known, and these term commitment, considerable resources and changes are mirrored not only in the long list a recognition of the benefits to be gained from of taxa assessed as threatened in England a more diverse and adaptable environment. v A Vascular Plant Red List for England Contents 1 Introduction 1 2 Coverage 3 2.1 Taxonomic coverage 3 2.2 ‘New Native’ species 4 2.3 Alien status 4 2.4 Hybrids 5 2.5 Geographic coverage 6 3 Data sources 7 4 Application of IUCN criteria 8 4.1 IUCN categories at the regional level 8 4.2 Treating England as a region 9 4.3 IUCN categories in England 9 4.4 Defining a population, individual and location 11 4.5 Conservation introductions 13 4.6 Methods used for assessing Area of Occupancy (AOO) 15 4.7 Methods used for assessing Extent of Occurrence (EOO) 17 5 Explanation of the England Red List 21 5.1 Species information 21 5.2 National responsibility and European edge of range 21 5.3 International responsibility 21 5.4 England endemics and near endemics 23 5.5 England Red List categories and criteria 23 5.6 Modification of England Red List categories 23 6 Results and discussion 24 6.1 Comparison of England, Wales and GB Red Lists 24 6.2 Taxa with a lower threat status in England than in GB 25 6.3 Taxa with a higher threat status in England than in GB 26 6.4 Taxa extinct in England 31 6.5 Ecological characteristics of threatened taxa in England 34 6.5.1 Ellenberg indicator values 34 6.5.2 Plant height 35 6.5.3 Broad habitat types 35 6.5.4 Major Biome Categories 37 6.6 Taxa reaching absolute northern or southern European range limits in England 38 6.7 Taxa assessed as LC in England but showing a marked decline when pre-1930 records are included 40 vi A Vascular Plant Red List for England 6.8 Declining widespread taxa assessed as Near Threatened 42 6.9 Taxa for which England has a particular responsibility 44 6.9.1 England-only taxa 44 6.9.2 Taxa for which England holds 75% or more of the GB hectad distribution, excluding England-only taxa 50 7 Examples of applying IUCN threat criteria 53 7.1 Critically Endangered (CR) 53 7.1.1 Phleum alpinum (Alpine Cat’s-tail) 53 7.1.2 Viola persicifolia (Fen Violet) 54 7.2 Endangered (EN) 54 7.2.1 Drosera anglica (Great Sundew) 54 7.2.2 Melampyrum cristatum (Crested Cow-wheat) 55 7.3 Vulnerable (VU) 56 7.3.1 Gentiana verna (Spring Gentian) 56 7.3.2 Crepis praemorsa (Leafless Hawk’s-beard) 57 7.4 Near Threatened (NT) 58 7.4.1 Herniaria ciliolata subsp. ciliolata (Fringed Rupturewort) 58 7.4.2 Koeleria vallesiana (Somerset Hair-grass) 59 7.5 Least Concern (LC) 60 7.5.1 Centaurium tenuiflorum (Slender Centaury) 60 7.5.2 Saxifraga hirculus (Marsh Saxifrage) 61 8 Vascular plant Red List for England 62 9 Excluded taxa 176 10 Acknowledgements 177 11 References 178 12 Appendix A Assessment of conservation status of English native Hawkweeds (Hieracium species) 183 vii A Vascular Plant Red List for England ‘It cannot be said too often that it is as much the conservationist’s job to keep common species common as it is to ensure the survival of rare species.’ N.W. Moore (1987) viii A Vascular Plant Red List for England 1 Introduction A Red List uses a globally recognised and Although this has the benefit of increased scientifically rigorous approach designed by confidence in the results, it also means that the International Union for the Conservation comparisons between GB and England threat of Nature (IUCN) to assess and determine statuses should be treated with some caution. risks of extinction. The method is applicable Wherever possible an explanation is given to all species and provides information on in the comments column on the Main List status, trends and threats. (Section 8) or within the text (e.g. Section 6.9.1) where clear anomalies have arisen. The production of a first vascular plant Red List for England follows similar Lists for This vascular plant Red List for England (from Great Britain (Cheffings & Farrell 2005) and now on referred to as the England Red List) Wales (Dines 2008) that have examined has been produced by the Botanical Society of changes to our flora since 1930 and identified Britain and Ireland (BSBI) and the Centre for those species most at risk. The threat to all Ecology and Hydrology (CEH). The research native and archaeophyte taxa in England is and writing of the report was funded by assessed using the same standardised IUCN Natural England and co-ordinated by a project criteria, thresholds and categories as for steering group comprising representatives the Great Britain (GB) and Wales Red Lists, from the BSBI, Natural England, Natural but the model used to calculate distribution History Museum, Royal Botanic Gardens trends has been replaced by a more sensitive Kew, Plantlife, and CEH, Wallingford. one that accounts for spatial and temporal Design and publication of this Red List was differences in recorder effort (see Section 4.6). funded by CEH and the BSBI. As is the case The River Mimram in Hertfordshire (Roger Cave). 1 A Vascular Plant Red List for England with all vascular plant Red Lists covering • It therefore follows that if a taxon is assessed regions within Britain and Ireland, this work here as being less threatened in England would not have been possible without the than it is in GB as a whole, its overall underlying field data collected in all weathers priority for conservation action in England over many thousands of hours of voluntary should be determined by its GB threat status time by skilled BSBI Vice-County Recorders, rather than by its status in England other voluntary field workers and amateur enthusiasts. • Taxa that are more threatened in England than they are in Great Britain should It is hoped that the England Red List will be naturally be considered as high priorities of use to a wide range of organisations and for conservation action within England, individuals. For example, it will help Natural even though it is accepted that they may be England to identify additional country-level considered a lower priority elsewhere in GB priority taxa requiring conservation action, whether through appropriate management When interpreting this England Red List, it is of Sites of Special Scientific Interest (SSSI), important to recognise that while the results designation of new SSSIs, targeting of agri- add greatly to our knowledge regarding the environment schemes and land management extinction risk to the English flora, those taxa advice in the ‘wider countryside’, or projects that have not been assessed as threatened funded by the Species Recovery Programme or NT using IUCN criteria may still be of (SRP).